What Facial Features Does the Pediatrician Look to Decide That a Newborn Is Feeling Pain?

Objective: The study aimed to analyze the gaze fixation of pediatricians during the decision process regarding the presence/absence of pain in pictures of newborn infants.

Study design: Experimental study, involving 38 pediatricians (92% females, 34.6 ± 9.0 years, 22 neonatologists) who evaluated 20 pictures (two pictures of each newborn: one at rest and one during a painful procedure), presented in random order for each participant. The Tobii-TX300 equipment tracked eye movements in four areas of interest of each picture (AOI): mouth, eyes, forehead, and nasolabial furrow. Pediatricians evaluated the intensity of pain with a verbal analogue score from 0 to 10 (0 = no pain; 10 = maximum pain). The number of pictures in which pediatricians fixed their gaze, the number of gaze fixations, and the total and average time of gaze fixations were compared among the AOI by analysis of variance (ANOVA). The visual-tracking parameters of the pictures' evaluations were also compared by ANOVA according to the pediatricians' perception of pain presence: moderate/severe (score = 6-10), mild (score = 3-5), and absent (score = 0-2). The association between the total time of gaze fixations in the AOI and pain perception was assessed by logistic regression.

Results: In the 20 newborn pictures, the mean number of gaze fixations was greater in the mouth, eyes, and forehead than in the nasolabial furrow. Also, the average total time of gaze fixations was greater in the mouth and forehead than in the nasolabial furrow. Controlling for the time of gaze fixation in the AOI, each additional second in the time of gaze fixation in the mouth (odds ratio [OR]: 1.26; 95% confidence interval [CI]: 1.08-1.46) and forehead (OR: 1.16; 95% CI: 1.02-1.33) was associated with an increase in the chance of moderate/severe pain presence in the neonatal facial picture.

Conclusion: When challenged to say whether pain is present in pictures of newborn infants' faces, pediatricians fix their gaze preferably in the mouth. The longer duration of gaze fixation in the mouth and forehead is associated with an increase perception that moderate/severe pain is present.

Key points: · Neonatal pain assessment is intrinsically subjective.. · Visual tracking identifies the focus of attention of individuals.. · Adults' gaze in neonates' mouth and forehead is associated with pain perception..